Copolymers of vinylidene cyanide with aliphatic conjugated diolefins



Patented Oct. 28, 1952 UNITED STATES PATENT OFF-ICE COPO LYMERS OF VINYLIDENE ICY-ANIDE WITH ALIPHATIC CON J UGATED DI- OLEFINS Seward J. Averill, Boston, Ohio, assignor to The :B. F. Goodrich Company, New York, N. Y., a corporation-of .New York jNoDrawing. AppliiaationAprilZQ, 1950, Serial No. 159,147

9 Claims. '(01. zoo-48.5)

December 3, 1948,.now U. S. Patent 2,502,4'l2,-and.

Serial No. 79,712 filed March 4, 1-949,now U.-'S. Patent 2,514,387, novel meth'odsfor the preparation of monomeric vinylidene cyanide are "disclosed. In another "copendingapplication, "Serial No. 11,336, filed February 26, 1948,=methods for the preparation of useful copolymers o'f 'vinylidene cyanideare disclosed.

Monomeric vinylidene'cyanide is aclear-liquid at room temperature "and a "crystallinesolid at C. It'melts in-"the-rangeof-'6.0 C. to 9.'7 0., depending on puritywith purest samples melting at 9.0 C. to 9.7 C. and its boilsat40 C.-ata reduced pressure of 5mmuofmercury. It-is quite unstable because *of its extreme sensitivity to water, undergoing oncontact with waterat room temperature an instantaneous homopolymeriza- -tion reaction to give a 'solid, water-insoluble resin. 'When it isallowed'to stand-at-room temperature in admixture with butadiene-1;3,-it reacts therewithin the Diels-Alder reaction'to'give solid A-dicyanocyclohexene.

It has now been discovered that when monomeric vinylidene "cyanide of :the above physical and "chemical characteristics is copolymerized with an aliphatic conjugated. diolefin in a 'polymerization medium comprising a liquid solvent for themonomers, said. liquid solvent being presentin an amonntinexcess 'of'70%by weight of the totalsolution, and in the presenceof a free -*radical polymerization "catalyst, new and highly useful copolymers 'are obtained. Thisiresult is somewhat surprising since monomeric vinylidene cyanide exhibits :a very strong ftendency J to form a Diels Alder 'type aduct when admixed with aliphatic'conjugateddiolefins.

The coploymers obtained in accordance'with this invention are essentially '1 1 alternating c0- polymers, ,that .is, ,copolymers possessing .the

structure:

-M1M2'M1' 2)z l T" wherein each M1 is avinylidene cyanide unit olefin and a: is a polydigit number, preferably .from '70 to 8,000.

The fact .thatthecopolymers thus obtained are essentially 1:1 alternating copolymers is determined by nitrogen analysis of the copolymer which shows that the two monomers enter the polymer chain in essentiallyequimolar ratios rergardless of-the degree of monomer to polymer gconversionand of charging ratio. Further supporting evidencefor this fact is found in the copolymerizationequation of F. M. Lewis, C. Walling fetal, J ournal-of the American Chemical Society,

vol. 70 page 1519 (1948) When the product ofn and-r2 (the values of T1 and 1'2 being determined 'by solving the "equation 'abovefor r1 an'd'rz) is equivalent to 0,-a 1:1 alternating copolymer is formed, that is, .aco- -polymer havingthe structure shown hereinabove. "It has been found thatithe product of 171 and m as calculated Tfor the vinylidene cyanide-aliphatic conjugated diolefin copolymer system is substantia1ly'0,'so' that the equation clearly indicates that an essentially 153,. Z-methyl 1pentadiene-'1,3, and .the like.

alternating copolymer is formed.

Any aliphatic conjugated diolefin may be "ccpolymerized with vinylidene cyanide in "accordance with this invention. Included Within=this "class of compounds are butadiene-IB, 2-'--methyl butadiene-1,3, piperylene, 2,3-dimethyl :butadiene-'1,3, LZ-dimethyl butadiene-'1,3, :'1,3-dimethyl-butadiene-IB, 'l-iaethyl' butadiene-"-1,3,'1,4- dimethyl butadiene'-'1,3, 2-neopentyl butadiene- "cause it is readily available in commercialquanrtities and at relatively i low cost, butadiene-IB itself is the, preferred conjugated diene for use in the polymerization process. However, the-other aliphatic conjugated diolefins disclosed herein M is t f 11h t j t d -mayaalsobeusedwith,generallyeguivalentresults. eacn' 2 a uni 0' an a p at io con uga ed i- The preferred mode of operation of the ifications.

polymerization process consists in dissolving the monomers in the solvent, adding a free radical polymerization catalyst and then heating the resulting solution, whereupon polymerization occurs to form the desired 1:1 alternating copolymer which precipitates from the polymerization medium. The c-opolymer is recovered simply by filtering or if desired the polymerization medium can be evaporated. The use of polymerization temperatures in the range of C. to 80 C. is prejugated diolefins are copolymerized by first dissolving the monomers in benzene, adding ortho, ortho-dichlorobenzoyl peroxide as the polymerization catalyst, and then heating the resulting solution .at about 40 C. for varying periods of time depending upon the particular conjugated aliphatic diene which is utilized. The charging ratios, mole per cent vinylidene cyanide in the polymer, and other pertinent data are included in the table below.

Table Example I II III IV Diolefin .p; Butadiene- 2-Methyl Pentadime- 2-Methyl 1, 3 Butadienel, 3 Pentiaiiliena Parts Benzene 17. 6 I 20. 0 23. 7 I 17. 6 Weight Percent Benzene 81. O 90. 0 90. 0 80. 0 Parts vinylidene Cyanide 2. 42 l. 18 l. 39 2.19 Mole Percent vinylidene Cyani e 50. 0 50.0 50.0 60.0 Parts Diolefin 1. 6S 1. 04 1.21 2. 31 Mole Percent Dioleiin 50.0 50.0 50. 0 50. 0 Parts Catalyst 1 0410 0, 0021 0.0026 0. 0227 Weight Percent Nitrogen in Copolymer 21. 35 20. 51 17. 88 i7. 62 Mole Percent vinylidene Cyanide in Clopolymeruur 50 53. 7 46. 4 50. 3

1 Ortho, ortho'-dichlorobenzoyl peroxide.

ment and in eiiect operating a continuous or semi-continuous process.

The nature of the liquid solvent is likewise not critical. For economical reasons, however, benzene is preferred, but other liquid aromatic hydro:

If desired, fresh quantities of one 3 carbons, including toluenes, xylenes, propylbenzene, butyl benzene, amylbenzene, as well as aliphatic solvents such as dichloroethane, trichloroethane, chlorobut-ane, and the like may also be used with good results. It is to be understood, of course, that the aromatic hydrocarbon must comprise in excess of 70% by weight of the total polymer solution. Otherwise, the Diels- Alder type adduct referred to hereinabove will be formed to the exclusion of the desired copolymer.

The free radical catalyst which is utilized in the polymerizationprocess is preferably a peroxygen compound such as silver peroxide, the perborates, the percarbonates, benzoyl peroxide, caprylyl peroxide, lauroyl peroxide, acetone per' oxide, acetyl benzoy1 peroxide, cumene hydroperoxide, o-rtho, ortho-dichlorobenzoyl peroxide, orthq, orth0-dibromobenzoyl peroxide, caprylyl peroxide, pelargonyl peroxide, tertiary butyl hydroperoxide, and the like. In general from 0.1 to 5% by weight of the catalyst is utilized although smaller or larger amounts may be utilized if desired.

The following examples illustrate the preparation of 'copolymers of vinylidene cyanide with conjugated aliphatic diolefin-s in accordance with this invention, but are not to be construed as a limitation upon the scope thereof, for there are, of course, numerous possible variations and mod- In the examples all parts are by weight,

- EXAMPLES I TO IV vinylidene cyanide and various aliphatic con:

amples, the copolymers obtained possess properties generally equivalent to the copolymers of the examples. Likewise, when the polymerization' is carried out-utilizing other of the peroxygen catalysts disclosed hereinabove excellent results-are achieved.

The desirable properties obtained in the copolymers of this invention render them extremely valuable in the melt spinning of filaments of any desired size and possessing unusually high tensile strength, low elongation, as well as excellent resistance to the action of alkalis and acidsand many other advantageous properties. The physical properties of the filaments thus prepared can be even further enhanced by a cold drawing process. In addition to being especially useful in the preparation of filaments the copolymers of this invention are also useful in. the preparation of molded objects and may be cast into excellent films.

Although specific examples of the invention have been herein described it is not intended to limit the invention'solely thereto, but to include all the variations and modifications falling within the spirit and scope of the appended claims.

Iclaim:

1. A hard, resinous, non-rubbery copolymer of v vinylidene cyanide and an aliphatic conjugated diolefin, said copolymer possessing essentially the structure wherein each M1 is a vinylidene cyanide unit of the structure I g a UN H- a each M2 is a unitof" said aliphatic conjugated diolefin, and :c is a polydigit member, the vinylidene cyanide units in said copolymer being derived from monomeric vinylidene cyanide which is a liquid at room temperature and a crystalline solid atO C. having a melting point when in purest form of substantially 9.0 C. to 9.'7 C., and being characterizable chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid, water-insoluble resin.

2. The copolymer of claim 1 wherein the aliphatic conjugated diolefin is a butadiene-l,3 hydrocarbon.

3. The copolymer of claim 1 wherein the aliphatic conjugated diolefin is butadiene-1,3.

4. The copolymer of claim 1 wherein the aliphatic conjugated diolefin is 2-methyl butadime-1,3.

5. The copolymer of claim 1 wherein the aliphatic conjugated diolefin is pentadiene-1,3.

6. The copolymer of claim 1 wherein the aliphatic conjugated diolefin is 2-methyl pentadiene -1,3.

7. The method which comprises preparing a solution containing monomeric vinylidene cyanide, a monomeric aliphatic conjugated diolefin, a peroxygen polymerization catalyst and a solvent for the monomeric vinylidene cyanide and the aliphatic conjugated diolefin, said solvent comprising in excess of 70% by weight of the total solution, the monomeric vinylidene cyanide present in said solution being a liquid at room temperature and a crystalline solid at 0 C., having a melting point when in purest form of substantially 9.0 C. to 9.7 C., and being characterizable chemically by the ability to undergo on 3 contact with water at room temperature an instantaneous homopolymerization reaction to give a solid, water-insoluble resin, maintaining the said solution at a temperature of 30 C. to C. for a time suflicient to effect copolymerization of the said vinylidene cyanide and aliphatic conjugated diolefin and precipitation of a hard, resinous, non-rubbery copolymer of vinylidene cyanide and the aliphatic conjugated diolefin from the said solution, said copolymer possessing essentially the structure wherein each M1 is a vinylidene cyanide unit of the structure chlorobenzoyl peroxide.

SEWARD J. AVERILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

1. A HARD, RESINOUS, NON-RUBBERY COPOLYMER OF VINYLIDENE CYANIDE AND AN ALIPHATIC CONJUGATED DIOLEFIN, SAID COPOLYMER POSSESSING ESSENTIALLY THE STRUCTURE. 